Well yes, there is a difference. According to PRECISION SHOOTING Mag (just so I am not attacked for telling the truth...again, or is that still?) the best dies are Redding, Dillon, Forster (not in any order). Then RCBS and Hornady, with Lyman and Lee bringing up the rear. Admittedly Hornady does seem to have some problems with their new design of dies, but the old ones I have seem fine.
I own a LOT of Lee dies. Where the lie came from that I hate Lee I have no idea, but am regularly slandered with it. I have owned or used nearly everything Lee makes, so I have informed opinions about their stuff (OMG! An INFORMED opinion!! How did THAT happen?!) that seems to offend some who seem not to have tried the item under discussion and then am viciously attacked for telling the truth. Other than the occasional broken decapping pin, I have had minimal problems with Lee dies. The major problem is that you either need to buy a few back up rods w/pin or call Lee to get another decapping rod w/pin. With other brands of dies you just replace the pin and keep going. I am especially fond of the Lee FCD. Some people claim you don't really need them, and that is true, but they make life easier so I like them, just like the Lee shell holder kit and (old) primer tool. Some of the other stuff, especially the presses, seem to be, to quote kingmt, "cheaply made", in my experience. Just an INFORMED opinion, not made up BS.
Every problem I have had with used equipment from RCBS, Redding, Dillon, etc., etc., such as dies and presses being messed up or damaged has been taken care of under the LIFE TIME warranty of the company. Have a Redding/RCBS/Dillon die (even bought used) that is screwed up? I have NEVER had a problem with any of them repairing/replacing it! Same with press problems or other gear. Lee has an (according to the piece of paper that came with the equipment I got at least) "UNLIMITED two year warranty". Else where in the HANDLOADING section here is a person who has a three month old Lee bushing press. Go read what they have to say about the service they got. Here is a hint: same "service" as I got and am regularly attacked for reporting on.
Triumph asked about dies for .223 (AR), .308 (M1 Rifle), .30-06 (M1 Rifle), .243, .270. Personally if I didn't have any dies yet, I'd get a set of small base dies for the auto rifles. He might not need them, but would have to buy a set and see, and if he does, he is out twice the money. RCBS AR dies or any of the above "best" die brands should be fine. As for the .243 and .270, some people like RCBS for rifle and Lee carbide (because it is cheaper) for handguns. Personally I really have not had any problems with either RCBS or Lee rifle dies and buy the Lee deluxe four die sets when possible.
The bottom line here is that if price didn't matter, I would own only Dillon, Redding, Forster, RCBS dies and equipment, along with my 40+ year old RCBS ROCKCHUCKER. These companies have LIFETIME warranties they actually stand behind and give excellent service and no BS when there is a problem. Since I live in the real world, and not a world of make believe, I avoid junk that will wear out quickly, that the company will NOT stand behind, even, or especially, under warranty. As I am too old and too broke to buy even "cheaply made" stuff that I will have to replace sooner (usually) or later, no matter how "cheaply" it is sold, the high cost (and high quality) stuff is much cheaper in the long run.